1. Field of the Invention
The present invention relates to an imaging lens and an electronic apparatus, more particularly to an imaging lens having five lens elements and an electronic apparatus having the same.
2. Description of the Related Art
In recent years, as use of portable electronic devices (e.g., mobile phones and digital cameras) becomes ubiquitous, much effort has been put into reducing dimensions of portable electronic devices. As dimensions of charged coupled device (CCD) and complementary metal-oxide semiconductor (CMOS) based optical sensors are reduced, dimensions of imaging lens for use with the optical sensors must be correspondingly reduced without significantly compromising optical performance.
In view of the above: U.S. Pat. No. 7,480,105 discloses a conventional imaging lens with five lens elements, of which the first, second, and third lens elements have negative, positive, and negative refractive powers, respectively; U.S. Pat. No. 7,639,432 discloses a conventional imaging lens with five lens elements, of which the first, second, and third lens elements have negative, positive, and positive refractive powers, respectively; and each of U.S. Pat. Nos. 7,486,449 and 7,684,127 discloses a conventional imaging lens with five lens elements, of which the first, second, and third lens elements have negative, negative, and positive refractive powers, respectively. However, the above conventional imaging lenses have system lengths ranging from 10 mm to 18 mm, which may be too long for use in certain miniaturized electronic apparatuses.
Moreover, each of U.S. Patent Application Publication Nos. 2011/0013069 and 2011/0249346 and U.S. Pat. No. 8,000,030 discloses a conventional imaging lens with a system length of approximately 6 mm, and having five lens elements, of which the first, second, and third lens elements have positive, negative, and negative refractive powers, respectively. However, due to surface configurations of the third, fourth, and fifth lens elements of each of the conventional imaging lenses, a satisfactory tradeoff between system length and aberration of the conventional imaging lens may be difficult to achieve. In other words, without significantly compromising the imaging quality, the system lengths of the conventional imaging lenses may not be effectively reduced.